A mini control system

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The DrMem Project strives to be a complete, easy-to-use control system for the hobbyist. This project is aimed at people that like to tinker and build programmable systems. Although commercial products will be supported, nothing prevents you from incorporating and controlling your own custom hardware.

DrMem has been developed with the following design goals:

• Reliability. Excepting hardware failures, this control system should provide 24/7 service in controlling and monitoring its devices. Like any project of this type, careful design and extensive testing will help prevent issues. However, DrMem is also written in the Rust programming language which provides strong compile-time checks which eliminate whole classes of bugs that occur in other languages. This project is an experiment in writing mission-critical code in Rust.

• Efficiency. Because we're using Rust, we have a systems programming language which generates optimal code and reduces CPU usage. Less CPU means reduced power consumption and less latency in responding to hardware inputs. In this project, we're also using the tokio async scheduler which means tasks will get distributed across all cores of the system, further reducing latencies (or providing more scalability.)

• Simplicity. DrMem is targeted for small installations so we want to minimize the number services that need to be managed. The drmemd executable, along with a configuration file that defines your location's set of devices, is all you need. DrMem also lets you define logic in its configuration so you don't need an external application to peform control loops.

• Accessibility. Although DrMem is capable running in the background with no user interaction, it is useful to have an interface that applications can use to provide dashboards, etc. for viewing and controlling DrMem devices. This is provided by a built-in HTTP server hosting a GraphQL interface.

What's Ready Now

Although DrMem is a young project, it's core is very usable. These are currently supported features:

• Two types of back-end storage
  • A "simple" back-end which only saves the last value of a device
  • A back-end which writes device information to a Redis server
• A client API which uses GraphQL
• Drivers which implement devices
  • 4 built-in drivers
    • Memory devices
    • Cycling device
    • Timer device
    • Map device (maps ranges of integers to values)
  • 4 external drivers
    • Weather Underground data
    • NTP daemon status
    • TP-Link support (tested with an HS440 Kasa light dimmer)
    • (Author's) custom sump pump monitor
• A "logic block" module that lets you define logic so that control loops can be set up internally, instead of requiring external client applications to do the controlling.

You can try some of this out by following the tutorial.

Other Control System / Home Automation Projects

If you're looking for more complete solutions that are available now, here are a few options:

• EPICS is a professional control system used by particle accelerators and observatories around the world.
• Mister House is a home automation system, written in Perl, that has been around for decades.
• Home Assistant is a nice-looking, well-polished, home automation system.
• Many devices can also be controlled by Google's Home app or Apple's HomeKit app

But be sure to check back occasionally as drmem matures!

Colophon

The name of this project, DrMem, is a shortened version of "Doctor Memory" -- a character from Firesign Theatre's comedy album, "We're All Bozos on this Bus". Doctor Memory is the marginally intelligent, easily confused AI that operates behind the scenes of the Future Fair.

Although this project strives to be much more reliable than this fictional character, I wanted to pay homage to Firesign Theatre's early vision of a powerful control system.

... this is Worker speaking. Hello.